The subject matter disclosed herein generally relates to methods of treating steel components and, more particularly, to a method and process of forming an improved steel component. Embodiments of the present disclosure are directed to steel component treatments and specifically to carburization processes of steel components made from steel having a composition of Fe-16.3Co-7.5Ni-3.5Cr-1.75Mo-0.2W-0.11C-0.03Ti-0.02V.
In the design and manufacture of steel components, and particularly gears, there is often a need to modify properties of the material. It is well recognized that carburizing is a process suited for hardening the surface and sub-surface of the steel component. Carburizing can be broadly considered as either an atmospheric carburization process or a vacuum carburization process. In the vacuum carburization process, the component is heated to an elevated temperature within a carburizing furnace under a vacuum, and a carburizing gas is introduced into the environment so that carbon atoms are diffused into the surface and sub-surface of the steel material. The carbon content in the surface and near sub-surface of the component is increased while the carbon content within the core of the component remains unaltered. The characteristics of the component have thus been modified to provide a hardened outer surface surrounding an interior core.
In response to the continued demand for new goods and services, engineers and scientists are always seeking to enhance products through material selection and/or process development. Stainless steel is widely utilized in many components in a vast array of products. One stainless steel of interest has a composition of Fe-16.3Co-7.5Ni-3.5Cr-1.75Mo-0.2W-0.11C-0.03Ti-0.02V, and one exemplary and available product is made under the trade name, Ferrium® C64™, and produced by QuesTek. As will be appreciated by those of skill in the art, the number preceding the chemicals is the nominal weight percentage, with the balance being iron.
In a carburizing process the time and temperature that the material is subjected to while in the carburizing environment will determine the surface hardness, case depth, hardness profile, and microstructure of the hardened portion of the material.
Gears are used in various industrial and technological applications to permit power transmission from one rotating or translating element to another. Each gear generally includes an array of gear teeth that mesh with the gear teeth of another gear so that the rotation or translation of the first gear can be transmitted to the second gear.
Existing gears may be heavy, and in aircraft applications, the weight of the gears may impact and/or limit the payload capability and/or range of the aircraft. Previous attempts to lighten the weight of gears resulted in gears that were not sufficiently robust to operate under operational conditions. For example, the technique of shot peening has been applied to the surfaces of the gears in order to produce a compressive residual stress layer and further modify the structural properties of the materials that formed the gears.